Introduction to pain
- Pain is a complex area that is poorly understood. The information below aims to get you to try to understand what the underlying cause for the pain is and how to choose appropriate analgesia. This may not always be straightforward and may require a bit of trial and error.
History taking in pain
- Aim to understand the exact nature of the pain, what triggers it and how severe is it specifically asking about the impact it has on their life.
- Try to ascertain whether this is an incident pain (pain brought on by a specific repeated activity) or breakthrough pain (pain breaking through a normally well controlled background pain)? Is this a complex multidimensional pain? (a combination of more than one type of pain suggesting that different analgesia is likely to be required).
- SOCRATES acronym may help with initial pain assessment:
- Site – where is the pain located?
- Can it be pointed to with a finger or is it described with the palm of a hand for example.
- Onset – does it come on acutely or gradually?
- Character – what is it like? Describe it?
- Radiation – does the pain move anywhere else?
- Associations – are there other symptoms related to the pain
- Time course – how long does it last for?
- Exacerbating/Relieving features – anything make it better or worse?
- Severity – how bad is the pain? (ask them to score out of 10)
- Site – where is the pain located?
- Are there psychological symptoms that may be worsening the pain e.g. anxiety or depression?
- Remember to ask what the patient normally takes for the pain and what has worked or not worked in the past. Make a note of adverse effects they have had with previous analgesia.
Types of Pain
- Acute – Starts to subside as healing commences and lasts approximately <3 months, usually responds well to analgesia
- Chronic – Does not usually relate to an injury, unpredictable response to analgesia.
- Total – emotional and psychological component in addition to disease (physical, social, psychological and spiritual)
- Nociceptive – noxious stimuli in periphery and involve inflammatory mediators. Good response to analgesia
- Somatic – Describe as ‘aching’ or ‘throbbing’, localised and constant. Good response to analgesia.
- Visceral – Describe as ‘sharp’ and constant, poorly localized. E.g. bowel colic. Usually good response to analgesia, though adjuncts may be required.
- Neuropathic– Damage to central or peripheral nervous system. Poor response to classic analgesics and often require adjuncts.
Examination in pain
- Always examine the patient! The aim is to treat the underlying cause of the pain.
- Has anything changed that might explain why the pain is worse?
- Do the clinical signs correlate with the history?
- Does this need to be investigated further?
Tip: Painful mouth or swallowing – examine for oral candidiasis. This is commonly missed and easily treated. Appropriate regimens include nystatin mouthwash (100,000 units QDS after food until lesions resolve) or oral fluconazole (50-100mg OD for seven days – monitor liver function).
Investigations in pain
- Does the patient have any imaging that may help to explain the pain? e.g. bone metastases or fracture, bowel obstruction etc.
- Are bloods normal?
- Renal function will be important for opiate dosing and if considering NSAIDS.
- Abnormal liver function may require paracetamol dose reduction
- Depending on the nature of the pain further investigations and imaging should be performed to help establish the cause (if it is not already known).
Tip: Always remember to check the calcium (especially in cancer)!
A framework for delivering bad news aimed at doctors doing PACES and medical student finals
Click here for advice on DNACPR decisions and click here to download free teaching notes on the pain assessment
Perfect revision for medical students, finals, OSCEs and MRCP PACES